From 830f5800acae17b972d264ab65fe54a7f10c1d82 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Tue, 4 Oct 2011 09:17:36 -0400 Subject: fix default __strnlen_user macro The existing __strnlen_user macro simply resolved to strnlen. However, the count returned by strnlen_user should include the NULL byte. This patch fixes the __strnlen_user macro to include the NULL byte in the count. Signed-off-by: Mark Salter Acked-by: Arnd Bergmann --- include/asm-generic/uaccess.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index ac68c999b6c2..9788568f7978 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -289,9 +289,14 @@ strncpy_from_user(char *dst, const char __user *src, long count) * Return 0 on exception, a value greater than N if too long */ #ifndef __strnlen_user -#define __strnlen_user strnlen +#define __strnlen_user(s, n) (strnlen((s), (n)) + 1) #endif +/* + * Unlike strnlen, strnlen_user includes the nul terminator in + * its returned count. Callers should check for a returned value + * greater than N as an indication the string is too long. + */ static inline long strnlen_user(const char __user *src, long n) { if (!access_ok(VERIFY_READ, src, 1)) -- cgit v1.2.3-59-g8ed1b